UROLOGICAL ONCOLOGY

doi: 10.1590/S1677-553820100003000025

A new multimodality technique accurately maps the primary lymphatic landing sites of the bladder
Roth B, Wissmeyer MP, Zehnder P, Birkhäuser FD, Thalmann GN, Krause TM, Studer UE
Department of Urology, University of Bern, Bern, Switzerland
Eur Urol. 2010; 57: 205-11

• Backgorund: Pathoanatomic studies have failed to map accurately the primary lymphatic landing sites of the urinary bladder.
  Objective: To use single-photon emission computed tomography (SPECT) combined with computed tomography (CT) plus intraoperative gamma probe verification to map the primary lymphatic landing sites of the bladder.
  Design, Setting, and Participants: Clinical trial of 60 consecutive cystectomy patients at a single centre.
  Intervention: Flexible cystoscopy-guided injection of technetium nanocolloid into one of six non-tumour-bearing sites of the bladder for preoperative detection of radioactive lymph nodes (LNs) with SPECT/CT followed by intraoperative verification with a gamma probe. Backup extended pelvic LN dissection (PLND) for ex vivo detection of missed LNs.
  Measurements: Three-dimensional projection of each LN site.
  Results and Limitations: A median of 4 (range: 1-14) radioactive LNs were detected per site and patient. Ninety-two percent of all LNs were found distal and caudal to where the ureter crosses the common iliac arteries. Eight percent were found proximal to the uretero-iliac crossing, none without simultaneous detection of additional radioactive LNs within the endopelvic region. Extended PLND resected 92% of all primary lymphatic landing sites; limited PLND resected only 52%. A few LNs may have been missed despite preoperative SPECT/CT, intraoperative gamma probe verification, and extended backup PLND.
  Conclusions: Multimodality SPECT/CT plus intraoperative gamma probe show the template of the bladder’s primary lymphatic landing sites to be larger than is often thought. PLND limited to the ventral portion of the external iliac vessels and obturator fossa removes only about 50% of all primary lymphatic landing sites, whereas extended PLND along the major pelvic vessels, including the internal iliac, external iliac, obturator, and common iliac region up to the uretero-iliac crossing, removes about 90%.

• Editorial Comment
  The authors of this very interesting study try to answer the question on the extent of lymphadenectomy in bladder cancer surgery on a scientific base. They detect the lymph node landing site of radioactive material injected into several areas of the bladder. Their conclusion is scientifically and clinically sound. As only 8% of “positive” lymph nodes were found cephalad of the uretero-iliac junction, and none of these was without a positive node in the caudal locations very, it is justified to limit the lymphadenectomy to the level where the retracted ureters cross the common iliac vessels. Still, the area to be explored is not “limited” and includes all tissue up to, on, and behind the external and internal iliac vessels and anterior to the presacral space. This paper is recommended reading for all urologic surgeons dealing with invasive bladder cancer.

Dr. Andreas Bohle
Professor of Urology
HELIOS Agnes Karll Hospital
Bad Schwartau, Germany
E-mail: boehle@urologie-bad-schwartau.de